Lamp



Jan. 29, 1935. L. w. BARNES l,989, 578

LAMP

Filed March 7, 1932 C c f l/ j zzzn ar' Patented Jan. 29, 1935 LAMP Leslie Walter Barnes, Newmarket, near Brisbane,

Queensland, Australia Application March 7, 1932 ln Australia March 24, 1931 1 Claim.

This invention is for improvements in and relating to lamps and refers more particularly to means for controlling the light from motor head lamps and the like.

I am aware that various devices, which include a series of plates (such as frustums and cylinders) arranged in the path of the rays, have been proposed, and although my invention contemplates the employment of plates for the control of the rays, I am not aware of an arrangement of them which is so eective for the purpose, or which is similar in the means of attaining the desired result.

I have found that with a reflector of ordinary construction and the employmenttherewith of thin plates specially contrived, I am able to so control the light that it follows a path and may be controlled to a certain distance and height ahead.

I accomplish the object of my invention by providing, for positioning n the lamp preferably at the back of the glass and in front of the re- Hector, a series of thin plates which are so arranged that there is or are one or morc flat straight plates in or near the centre and concentric or nearly concentric semicircular or curved plates above and/01' below whose ends are securedeto the said centre plate 01' plates, all of which are nonreilecting on the upper sides and reflecting on the under sides.

The preferred shape of the lower curved plates is half the section of a hollow cone lying between two parallel planes which are parallel with the base, or which are at an angle to the base.

The preferred shape of the upper curved plates is similar to the lower plates.

The blades in the upper part of the lamp are so mounted that the longer edge is at the back, While in the blades in the lower part of the lamp the longer edge is at the front.

Furthermore it is found desirable that the difference in length of the edges in the upper plates be greater than in the lower plates, and that the said difference in length n the upper plates be progressively greater from the centre of the lamp; and progressively lesser from the centre of the lamp in the lower plates. And furthermore, the width of the plates n the 'top and bottom of the lamp should progressively increase stepwise so that the outer plates are narrower in width and the inner plates are wider in Width and are nearly touching the bulb.

In order that the invention may be better understood reference will be had to the accompanying drawing, wherein:-

(Cl. Z m-48.4)

Figure 1 is a embodying this ATENT OFFICE Serial No. 597,347

sectional side elevation of a lamp invention.

Figure 2 is a front elevation of the same.

Figure 3 is a horizontal section on the line 3-3 of Figure 2, looking downwardly.

Figure 4 is an enlarged perspective View of a portion of the lamp.

In the drawi ngthe upper blades or plates A and lower blades or plates B are secured at their ends to the str aight, flat centre blades C. The

whole is thus assembled and may be placed within the lamp in front of bulb D and reflector E. It will be understood that preferably a large number of very thin blades is employed whereas only a small number is shown for illustration.

In the drawing the plates A and B are half sections of a hollow cone lying between two parallel planes which are parallel with the base but in the case of plates A are also curved in their width. The front edges A' A are shorter than the rear front edges B' than the rear e of the upper blades edges A while the of the lower blades B are longer dges B (see Figure 2). The centre plates C are straight and project rearwardly to within a suitable distance from the bulb D. In use the tilt of the lamp will determine whether they are in a horizontal plane or otherwise.

construction as A shown in the drawing will permit of light passing between the thin plates but the path will be downward at the predetermined angle. Those and which are rays which would normally rise most objectionable will be most deflected downward while those rays which would normally project downward at or below the desired angle and which are not objectionable will be but slightly deilected, if at all.

At the same time rays from the sides of the plates A, that is where they meet and approach the plates C, will cross and illuminate the sides of the road near the front of the car.

In some case below the central flat I claim: Means for co s I may dispense with the plates plates.

ntrolling the rays of light in motor car headlamps and the like, consisting of upper and lower series of concentric half frustum plates which are oppositely disposed and centrally arranged flat anchorage plates to which the ends of the concentric half frustum plates are respectively secured, the plates in the upper series being so mounted that their longer edges are at the back and the plates in the lower series being so mounted tha of the lamp.

t the longer edges are at the front LESLIE WALTER BARNES. 

